


Suptober Day 25: Villain

by tiamatv



Series: Promptober 2020 [24]
Category: Supernatural
Genre: Alternate Universe - Fantasy, Arranged Marriage Politics, Cecaelias, Creature Castiel (Supernatural), Dean Winchester Needs to Use Actual Words, Emotional Hurt/Comfort, John Winchester Being an Asshole, Loving Marriage, M/M, Possessive Castiel (Supernatural), Prince Dean Winchester, Rough Sex, Top Castiel/Bottom Dean Winchester, Top/Bottom Versatile Castiel/Dean Winchester, octo!cas
Language: English
Status: Completed
Published: 2020-10-26
Updated: 2020-10-26
Packaged: 2021-03-09 00:28:23
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 9,069
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27205229
Author URL: https://archiveofourown.org/users/tiamatv/pseuds/tiamatv
Summary: “Get back to the table, Dean. You won’t disrespect our guests like that,” John Winchester booms, and Dean’s spine goes rigid.Pretty much the first and only time Dean defied his father was when he chose to marry Cas.Looks like there’s going to be a second.(The return of Octo!Cas and Prince Dean, in the same universe as Day 7: Tentacles. No actual tentacles in this one, though.)
Relationships: Castiel/Dean Winchester
Series: Promptober 2020 [24]
Series URL: https://archiveofourown.org/series/1954990
Comments: 36
Kudos: 172





	Suptober Day 25: Villain

**Author's Note:**

> Soooo this started as cutesy tentacle husband fluff that I intended to spike with just a bit of plot, and then it got hurty. And then it grew porn. Ay ya yay. I legitimately have no idea if this story is going to make sense to anyone but me, but this was what wanted to be written today, I guess.
> 
> No actual tentacle sex in this one, but they do talk about it, and Cas's true form is, of course, a cecaelia. 
> 
> TW: There’s also some rather rough sex in here with… insufficient consent, I suppose? They’re both very into it, and Dean explicitly says yes when asked, but it’s definitely not negotiated beforehand.

Dean likes that Cas is different—that he looks at everything with new eyes. He sits in sunlight for hours, his face turned up to it—never gets sunburned either, because, well, weird, but no-one’s seemed to notice—and loves flowers more than anyone should. It’s not uncommon for Dean to find him out in the garden tootling around with Joshua, curling bare toes in the soil. He might think toes are weird pretty much forever (“Why are there ten? And they’re all so _short,_ they don’t seem to have enough joints.” “Well, you’ve got eight sea-arms with no joints at all, why are there eight?” “You ask the strangest questions, Dean”) but he really likes being barefoot.

Dean comes out to the garden to wipe off the sweat and come find his husband after running drills with the soldiers—because of course Cas is in the garden again; Dean’s ego is only a _little_ bruised that Cas didn’t come and watch him today. His husband is sitting on one of the small wooden benches set up in one of the big back gardens, staring very intently at an arm that he’s got raised in front of him.

Alright, that’s weird even for Cas—especially since his other form _has_ the normal up-top kind of human arms, so nothing about that is new.

Then Dean realizes that there’s maybe half a dozen huge fucking bumblebees perched on his husband’s _bare arm_ , and he almost has a heart attack. In fact, since Cas is wearing long sleeves, he must have _pushed up_ his sleeve to let them sit there, oh fuck _no_.

“Cas…” he says, shakily. If he comes closer, is he gonna scare them into stinging? “Cas, sweetheart, what are you doing?”

Cas looks up at him and smiles, faintly, that little tip of a corner of his mouth. His arm doesn’t move, though, thank the goddess. “Aren’t they cute?” he says, simply. “I like them, they’re fuzzy.”

“Uh, yeah, so are the kittens in the stables,” Dean says, shakily. He doesn’t know if he wants to run in and grab Cas real quick, or just not move at all so he doesn’t freak out the death bugs. (It doesn’t escape Dean that his automatic reaction is to get his husband out of there and go, not just… go, but by this point knowing that doesn’t bother him much anymore.) “Maybe you could play with those, instead.”

One of the bees wriggles its butt and crawls up a little further on Cas’s arm, and Dean flinches.

“Yes, exactly,” Cas answers, serene as anything. “They are all very adorable. And the kittens have little claws and teeth as well—they’ve punctured through my clothing—so why are you so concerned about some bees? They’re very small.”

“Bees actually _sting_ ,” Dean points out.

“I know, Joshua told me. But so do blue-ringed octopuses, and I think they are cute, as well.” Cas answers, cheerfully, “Well, they don’t sting, exactly. They bite, though. They can kill most things in a bite because of the toxin in their salivary glands.” He looks up at Dean, taking his attention away from the insects crawling on his arm. “I had one as a pet growing up, but they don’t live very long. She killed a barracuda once.”

Uh. Yeah, that’s not making Dean feel any better about the bees. Not in _any way_. Also, considering that Cas has _octopus arms_ in his normal form, isn’t it weird that he had a pet octopus? There’s about a fifty fifty chance that Cas is going to insist on sleeping in the bathtub again with all his sea-arms curled around him in a hostile waving tetacly shell if Dean asks something like that, though.

“You…” and this is where Dean gives up, because he knows which one of them is the stubborn one, and it’s not the one of them who’s actually been living above the water all his life and should technically know more about bees. “Why are they all… sitting on you like that?”

Cas smiles and lifts one of the fat insects off his skin with a finger—Dean flinches at that again—but after a second of sitting on the tip of Cas’s finger, the bee just takes off, weaving like it’s drunk. “I think they like the taste of my secretions,” Castiel notes, absently. Carefully, he nudges each bumblebee, one by one, and they wobble off through the air. Cas watches them go with the damned sweetest smile.

Secretions. Huh. Dean opens him mouth to correct him—isn’t that just sweat?—but now that he thinks about it, he’s not actually sure that Cas… sweats. He doesn’t think he’s ever seen that, even with all the hours that Cas sits in the sun. Crap, is he going to have to worry about him getting overheated in summer or something? It doesn’t get _that_ hot here in Lebanon…

Cas is smiling up at him. He pats the bench beside him. “You are thinking so hard your hair’s floating,” he says, warmly. “Come sit.”

“Hair doesn’t do that,” Dean points out, but he sits beside him.

Castiel rolls his eyes like _Dean’s_ the one being ridiculous. “Of course it doesn’t, it sinks when it gets waterlogged. It’s just an expression.”

Dean glares, and Cas can’t—or maybe he just doesn’t—keep himself from snickering.

So it’s his own damned fault that Dean reaches out and licks him behind his ear.

“Huh,” he muses. “You do taste kind of good.”

Not that Dean didn’t already know that. He’s had his mouth _all over_ Cas’s body. But it’s really damned nice to be reminded.

“I do,” Cas agrees, shamelessly, and his smile widens. “Do you? Let’s find out.”

There’s only so much fooling around in public that the people of Winchester House will tolerate from them, though. Dean wants to maintain that _yeah_ , they’re still fucking newlyweds (probably). But he’s not really a fan of Ellen pointing out that at this point, they’ve been married for longer than their _courtship_ was, so it really doesn’t count anymore.

So Dean does enjoy it for a little while, but he grudgingly nudges Cas away from his neck and his shoulders when Joshua clears his throat, gently.

(Could be worse. Jo would have just gotten a bucket. Besides, Cas’s pout is cute.)

But that’s the thing. Cas _is_ different, and he’s sometimes a little… off. He’s better at faking, now and again, but he still slips. The staff of Winchester house are all used to him by now, though—Dean was always the one who got all the gossip from everyone in the first place; if someone had a problem with his husband, Dean has no doubt that a person who’s walloped Dean with a spoon or someone else who’s seen him fall ass-first into a manure pile would come straight to him.

Their people might not know the whole story—they sure as hell don’t even know _part_ of it—but they know some very serious shit went down not long after their wedding, and that Cas is the one who put himself between Dean and it. Cas is the one who brought Dean home. He’d have earned their loyalty for that alone—even if no-one except Sam knows that Cas is the one who saved him from the deep water long ago, too, back when Dean was still heir to Lebanon, and what price Cas paid for that.

(If the good people of Winchester House don’t know that Cas put himself between Dean and the Cas’s crazy kraken uncle who was planning to spell Dean, so he could drag him underwater and get Cas to execute him in front of some sort of cecaelia army, well, that’s probably for the better. It’s a hell of a romantic story, Dean admits it, but it’s _really_ fucking complicated.)

But Castiel’s a Winchester prince now, and around here, that means something.

Ellen says, “Well, ain’t he precious?” and if she were talking about anyone else, it would be sarcasm. About Cas, it’s not. He’s awkward—oh, for sure—and so blunt that Sam mutters about it. But he’s _genuine_ , and it’s so fucking refreshing after a lifetime of court and politics. Sometimes, when someone—most often Dean’s dad, if Dean’s being honest, or one of the court advisors—says something that’s just plain bullshit and Cas just _calls_ them on it, just like that, it’s all Dean can do to not grab him by the chin and cover his face with kisses.

(Dean is almost a hundred percent sure that’s not because cecaelias don’t lie, though. He’s _met_ some of Cas’s relatives. It might just be Cas.)

But Dean’s husband is also gentle, and for every bit of patience he doesn’t have with politics—a grand total of ‘fucking none’—he’s got every bit of it for just… people. Dean’s not the only prince nowadays who might be found sitting on the edge of the the town fountain with his feet in the water, surrounded by half a dozen kids doing the same, and talking happily with them about how good it feels. Or being late to dinner because he’s helping someone prop up a cart to help change a wheel, or talking softly to a horse that’s thrown a shoe while it gets its foot checked out. Or walking around their little weekly market with someone’s toddler clinging, giggling, to his back like Cas doesn’t even realize the kid’s there.

(Dean is pretty sure no-one’s realized just how strong Cas is; Cas, of course, notices that the kid’s there, but _keeping_ the kid there is pretty effortless for him.)

But that sweetness is also the most freaking incongruous thing in a guy nearly Dean’s height, so damned handsome that there are days Dean’s startled to wake up to that face (and not just ‘cause Cas needs less sleep, so most mornings when Dean wakes up, those big blue eyes are already staring right into his face).

It was a little creepy, until it wasn’t. The last time Dean woke up with Cas turned towards him and his eyes still closed, lashes shading his cheeks in the soft early morning light, Dean was actually worried for a little bit.

So yeah, Lebanon loves him, even if the council probably wants to throw him even farther out the window than they want to throw Dean, and Dean _knows_ just what his dad thinks of Dean’s husband. But even most of their visitors think he’s “charming” and “original,” or at least that’s all anyone with brains is willing to say anywhere in the hearing of anyone attached to the name Winchester.

So Dean doesn’t actually think too much of it when Sam, a little nervously, tells him that their dad invited _Amara_ to a reception dinner.

“Fuck,” Dean sighs, and he’s not _pleased_ , but… here they are.

He wishes he were surprised—hell, he wishes there were more _time_ —but they had more time than he expected, considering how hard Amara’s asshole brother was pushing for an alliance before any of this shit went down.

Oh, and the fucking arranged marriage. Yeah, there was that.

“Is Castiel going to be okay tonight?” Sam asks, and there’s a gentleness in his tone that makes Dean both want to hug him and also douse him in alcohol at the same time. “I didn’t have a chance to look at the seating arrangements before they went off to final.”

Seating arrangements. _Shudder._ Yeah, Sam’s _much_ better suited to this kind of political bullshit than Dean ever was.

Dean shrugs it off, though. That’s kind of weird. “Huh? Why wouldn’t be?”

Sam’s eye roll is so dramatic it should make that long hair of his float in that way that Cas says is ‘just an expression.’ “Uh, because she and you were _engaged?_ Remember?”

“Tryin’ to forget, actually, so thanks.” Dean rolls his eyes back. Holy fuck, that seems a really long time ago, now. “C’mon, you know that wasn’t real. Cas’ll be just fine.”

The fact is, though, for all that Cas is Dean’s sweet guy who’s funny about insects and now and again sticks his foot—weirdness of toes and all—into his mouth, Dean doesn’t think by any means that Cas is a _pushover_. He’s really… just not. For one thing, Dean, more than anyone in Lebanon, has _seen_ what happens when someone pushes him: just because a cliff face might be smooth and sun-warmed doesn’t mean it’s gonna _give_. For another, Cas was born to a species where they survive on their own in the ocean open basically from the moment they come out of their eggs.

(Eggs. Yeah, Dean’s not thinking too hard about that. Thank the goddess they’re both male—and yes, Dean had a panicked moment of confirming with Cas that the males of his species _don’t_ produce eggs, because nature is fucking weird sometimes. Cas laughed so hard he had to sit down.)

Yeah, anyone who thinks they can step on Cas is probably gonna end up drowned in the nearest bay.

So if Dean’s ex-fiancée from a marriage that Dean really wanted no part of tries to stir up some shit—and Dean doesn’t think she will, ‘cause what would even be the point of that?—Dean knows who he’s grabbing onto first to prevent serious damage being done. And it’s not gonna be _her_.

Dean regrets thinking that a little, though, when he finally _does_ see the seating arrangements. Yeah, he gets that he and Cas can’t sit together and be disgusting at every damned dinner—especially since Dean’s completely off the table now when it comes to flashing his pretty smile and softening up someone’s daughter, someone’s wife, before they ever get to the negotiating table. Sure, he’ll still smile, and he’s happy to help—he can be sociable even if he’s fucking stupid at being political. He’s pretty sure that’s why he’s currently seated where he is, between Lady Kate, of the wolf shifters to the far north, and Demoiselle Eileen. Fortunately, he likes both of them well enough that it’s going to be no trouble to smile and chat them up.

But Dean’s only really got eyes for one guy, thanks, and _that_ one is his by law and by the ring that Cas wears around his neck.

So whoever thought it was comical to seat Dean’s husband next to Dean’s _ex-fiancée_ is going to get a long talking to. Possibly a punch in the face.

Still, he warily watches Cas make his little bow to Amara—Cas still hasn’t got the hang of dropping his eyes when he does that; oh well—and Dean remembers Amara being kind of intense, but pleasant enough. Her expression is all calm when she bows back, and whatever Cas says to her obviously isn’t too weird, because she smiles and answers.

Well, alright. Cas is a big cecaelia on legs; he can handle himself.

By the time dinner is most of the way over, Dean knows that the way to get Lady Kate on board with an alliance with Lebanon is through her little sister. He also knows that Eileen has a _serious_ crush on Sam—damn, she could do _so_ much better—and he can’t wait to tell Cas about it. Those two are going to be so fucking cute.

But conversing with the two of them does take more work, because he’s got to make sure he’s facing towards Eileen when he talks to her, and Lady Kate is sometimes a little hard to understand when she talks around her eyeteeth (and Dean knows better than to watch a wolf shifter eat if he wants to be able to finish his own dinner).

So he’s a little surprised to look across the table to find Amara smiling and talking to someone Dean doesn’t know, on her other side, and Cas’s place setting empty, his fish course—two courses ago—only half-finished. It’s true that Cas doesn’t really like cooked fish, much, and that’s never going to stop being a little hilarious. But he also puts away more food than anyone his size looks like they should, and he’ll normally clean pretty much any other plate.

Dean’s husband doesn’t come back.

One course later, Dean stands up and starts making his pretties and saying good night. Yeah, before dessert. Sam’s looking worried now, too, sitting near the head of the table, and _he_ doesn’t look like he believes Dean’s plastered-on smile.

Just like Dean doesn’t believe Amara’s, when he gets to her—because he can’t just leave the table without acknowledging the sister of the ruler of a major principality that borders much smaller Lebanon.

The idea that he was supposed to marry her, before he met Cas, seems very far away. They didn’t know each other—sure, they met once or twice, but that was it. It wasn’t that Dean ever _wanted_ to, but he figured that agreeing to this, an old-fashioned arrangement with this woman who was born to politics and who the council approved of and picked for him, was probably the best way to keep himself from running Lebanon to the ground when he had to take over.

He sort of imagined it was the same for her; why else would she want to tie herself to the dumbass from a much smaller kingdom whose only qualification to rule was being four years older than the smarter brother?

But the expression that’s on her face now, looking up at him, isn’t nice. Her high cheekbones make it look like a mask. Her brown eyes have a glee in them that sends a chill down Dean’s spine.

He once asked Cas if the expression ‘shark smile’ means anything to him. Cas answered, very seriously, “Sharks don’t smile, Dean, they’re just too stupid to.”

That memory is the only thing that lets Dean keep his cool when this one is pointed right at him.

“Dean, so good to see you again,” she murmurs, and Dean can’t believe he ever once thought that she was beautiful. “Wasn’t dinner divine? Dear Ellen really outdid herself this time. I never _did_ get the chance to ask her for the recipe for her bolognese, though. It really is such a pity our engagement… fell through.”

Dean stares at her, blindsided, punched. Okay. He might not know much at all about politics, but even _he’s_ sure that mentioning those circumstances is _not_ the thing that anyone does in polite company. And ‘Dear Ellen?’ Yeah, no, Amara Shurley of House Shurley doesn’t get to pretend she knows _anyone_ in the Winchester household. And sure as hell not the chatelaine who had as much of the raising of Dean and Sam as their dad, after their mom died.

Amara sighs a little, but the smile never fades. “Your new husband is very… sweet, though,” she trills, high and shrill. “How lucky you are! He cares about you very much. It’s a pity he wasn’t feeling well, is he alright?”

Dean doesn’t want to make a scene. He knows that’s what someone wants—this is a set-up, and he has a twisting, painful, gut feeling he knows who it is.

And it maybe isn’t Amara.

Dean thinks he makes the goddess and his little brother proud when he just bows silently to her—and for the first time, he understands exactly why Cas doesn’t drop his eyes to the ground when he lowers his head. You don’t look away from something that might just try to take your head off.

But Dean’s all the fuck out of court graces, after that, and he doesn’t make any more goodbyes. He’s through the door leading into the living quarters before he hears the heavy thump of boots double-timing behind him. He grits out, “Sammy, shit. Look, I’m sorry, I know, I just gotta—"

“Get back to the table, Dean. You won’t disrespect our guests like that,” his dad booms, and Dean’s spine goes _rigid_.

Pretty much the first and only time Dean defied his father was when he chose to marry Cas.

Looks like there’s going to be a second.

He turns around, slowly. He turns slowly because if he doesn’t, his momentum is going to have his fists up and swinging. “I don’t know what you did,” Dean says, in an angry rumble that he’s pretty sure would make someone start looking around for Cas himself. “And I don’t know what Amara said to him, but whatever the fuck it was, you’d better _hope_ Cas is just fine.”

John Winchester’s lip curls almost invisibly under his beard before he straightens it again. “I don’t know _what_ you think anyone did to Castiel, Dean,” he answers, coolly, “but you can’t blame Lady Amara for being upset. She thought she was going to be High Lady of Lebanon, after all, and _you_ broke the engagement to marry… well, a nobody.”

Yeah, Dean gets that. To be honest, she probably _does_ deserve some kind of apology from him, and Dean’s an ass for not thinking about that sooner. And, frankly, if he had a douche of a brother like hers, he might agree to an arranged marriage to get away from him, too.

But Dean is done. He smiles, and it’s not nice. “Everyone thinks I’m the dumb brother, and you know what? I am. But, you know, I almost married her?” he jabs a finger at the door at the end of the hallway. “And I almost did because she knows how to play a game I’m _really_ bad at.”

He’s not sure when he realized he and his dad were the same height. But they are. They’re both big men, and today, he’s his own man. Dean’s not afraid of John Winchester anymore.

Dean hisses, “She’d have to be _pretty fucking stupid_ to insult one of us in our own house unless someone _around here_ told her that they’d back her. Amara Shurley is a lot of things, but she is not stupid.” And he tilts in, using his body, his shoulders. The formal gear he’s wearing is strangling, too tight, and he rips off his cravat in one sharp motion. “So let me tell you this now. I’m gonna go find Castiel, _Dad_ , because _my marriage_ is more important to me than whatever face-saving you’re trying to tell yourself you’re doing here.” Dean breathes in, and out. “And if Cas leaves me over whatever _bullshit_ you let her tell him? I’m not agreeing to a divorce. I’m sure as fuck not taking her back. _I’m_ leaving, and I’m not comin’ back until _he_ does.”

“ _Dean,_ ” his dad booms. “You’re a Winchester prince, you—”

Dean settles his body straight, neutral, hands at his side. He’s feeling strangely calm, actually. Probably because he means it, he means every word.

Amara’s not the villain in this story.

“I don’t give a fuck about that,” he says, very softly, “if my husband’s not considered a Winchester prince, too.”

He turns on his heel and leaves before he socks his dad in the face.

Sammy should be _really_ proud of him.

But Cas is standing in the middle of their suite of rooms when Dean blasts into there, calling his sweetheart's name with increasing panic. His relief at _finding_ him still there is a cold-water shock. Cas goes to water when he’s upset, which Dean understands, but he’s going to break his neck if he tries to ride in the dark.

Dean’s so relieved that it takes two steps in, the door closing behind him, and two deep breaths before he even realizes that Cas is _completely buck naked._

Wow. Okay. Okay, Cas doesn't like tight clothes in general, and he is probably the only person Dean knows who hates formalwear more than Dean’s Uncle Bobby, but… he doesn’t normally go down to _skin_ like this unless he’s in the bay or in the bath, he knows better—

“Dean,” his husband says, and it’s not a greeting.

Cas’s voice is always so damned deep; Ellen says it’s like faraway thunder, but Cas is so angry when he turns around that there’s literal lights sparking in his irises that are visible even in the soft warm lamplight, a hot flush on his cheeks. He has his legs braced just a little apart, his heavy thighs not touching and fully on display, and his head thrown up and back, his chin high.

Dean’s husband is so goddamned hot, naked and furious and a little terrifying, that Dean’s body doesn’t even know what to do with that.

 _Okay._ Bad timing. Terrible fucking timing. Nope.

“Are you okay?” Dean asks, and hurries in, his arms already coming up to hold, to have. “Goddess bless, Cas, you left dinner, and I thought—"

Cas steps back from him, and Dean stalls where he is, the relief in his mouth souring.

That’s never happened before. Dean doesn’t know what Amara told Cas, and okay, he thought, he _really_ thought, that Cas was going to just maybe be a little pissed at _her_ —he’s so sweet-tempered, normally. Maybe Cas walked to keep from doing something stupid, the way Dean had to walk away so he didn’t belt _either_ his dad or a guest in their home.

But the fury in his husband’s eyes isn’t pointed out the door. It’s pointed at _Dean_.

“Is it true?” and the voice that rolls across their room is low and alien enough that it rattles the base of Dean’s spine.

Yeah, Dean does forget sometimes: Cas isn’t just a warrior, and he’s not exactly human. His kind are _predators_.

Dean straightens up where he stands and answers, “I don’t know what she told you, Cas, but I swear to the goddess, whatever it was—”

“That she was your mate _,_ ” and that one is a snarl. “That you were _hers_ to have.”

Dean breathes out a deep, shaky breath of relief. Yeah, okay. Thank the goddess, he knows the answer to that one.

“No,” Dean answers, honestly, and he punctuates it by shaking his head, sharply enough he thinks his brain rattles. “No, that wasn’t—that was _never_ true. Of course I was never her _mate._ I never slept with her—fuck, never even kissed her, sweetheart.” He takes one careful step forward, and Cas doesn’t back away this time. He takes one more. “You gotta believe me about this. Look, what else did she say?”

Cas’s shoulders, hitched high and defensive, start to settle. The icy sparks start to flicker out of his eyes, leaving them that beautiful deep blue that Dean loves so much, and so tired that it makes Dean’s bones ache. He relaxes with a small breath. His chin dips again. “She said… she said you were promised to her,” he says, and there’s a sad ache in it that makes Dean just want to rush in and cuddle him, nakedness and all. “That… that you were her intended husband, and I stole you. Oh, _Dean._ ” He closes his eyes. “I’m so happy it’s not true.”

Dean hesitates. Oh. Oh, okay, shit. Dean’s never been exactly sure what, in Cas’s head, the difference is between ‘mate’ and ‘husband,’ since he uses them both pretty interchangeably, but Dean always thought that was because, well, he and Cas have _a lot_ of sex. Maybe there isn’t a difference to him. “I…”

He trails off. Dean has no fucking idea what to say to that. It _isn’t_ true, of course not, Cas didn’t _steal_ him. Dean fell in love with the weird little guy he found looking out over the ocean, and he wasn’t going to settle for something stupid and political when he could have something so much _better_.

But in some other way, it… kind of is true.

Cas’s eyes come back open slowly, in the awkward silence. He studies Dean’s expression, and the slow horror dawning in his face is _awful_. “Oh,” he whispers. This time, he steps back quickly enough that he stumbles, clumsy on his feet the way he still gets when the night is late or he’s tired. He trips on the puddle of clothes around his feet, and before Dean can catch him, he topples.

Dean’s not too shocked to jerk forward, hand out even though he’s too far to do anything about it, but Cas knocks against the edge of the bed and sits down on it. The items on the coverlet jump as Cas’s weight hits it.

A bright blue feather, a handful of the volcanic geodes Lebanon is famous for, in purple. A tiny, hand-sized pillow stuffed with kapok, so squishy Cas couldn’t stop holding it to his cheek. A piece of dark green silk. Rosewood knitting needles. A small gold coin so old and soft whatever pattern was on it is long gone. It’s the contents of what Cas calls his ‘cache’ and Dean teasingly refers to as his ‘treasure box.’

A strangely shaped, curved satchel with a deep flap and a long tie is sitting near the pillow. It has a shiny, oily covering that Dean knows is made out of some kind of whale skin, and it’s shaped that way so it doesn’t get in the way of Cas’s sea-arms or drag in the water. Cas pulls it towards him, moving slowly, like something inside him hurts.

“I can’t take most of this with me,” he says, dully, and nudges his treasures into a small pile. He pushes a finger into the center of the small pillow and watches the imprint of it disappear. “They wouldn’t survive the ocean.”

No. No, no, _no_.

Because Dean knows. He knows that if Cas leaves, it’s not a divorce Dean’s looking at, it’s an annulment for abandonment, because he can’t follow where Cas would go. None of them can. If he disappears, Dean will never be able to find him again.

Dean crosses the room so fast he doesn’t remember taking the steps, and hits his knees in front of his husband so hard that the shock of it jolts his hips. He doesn’t notice. He grabs Cas’s hands in his before Cas can yank them back—but Cas isn’t human. He doesn’t try.

“It’s… complicated, sweetheart, okay?” Dean pleads. “Look, I… it was an arranged marriage. It didn’t even happen.”

Cas looks down at him, blankly. “I don’t know what that means. You know I don’t.”

No, of course Cas wouldn’t. Dean blows out a breath and drops his head, resting his forehead against their joined hands, his chin in the dip between his husband’s thighs. Vaguely, at the touch of skin and skin, he remembers that Cas is naked. At another time, he thinks Cas might stroke his shoulders or play with his hair, because he’s the most touchy-feely man that Dean’s ever met, but he doesn’t. His hands are very still in Dean’s.

Dean swallows, and raises his head, because he really can’t hide anymore. “It means, uh… that… we didn’t… I didn’t know her, not really, but our families wanted her and me to be… together.”

He can’t read Cas’s expression when he’s looking that far away, that alien. He knows that Cas can see across miles underwater, and he looks miles away now.

“But they didn’t want _us_ to be together.” His sweetheart’s voice is still so unmistakably his own, but the thunder of it isn’t thick with electricity and lightning and a tornado on the deep blue sea anymore. It’s smaller than Dean has ever heard it. “She said… I am strange, and nobody. That when you chose me, you lost your… your heritage. And a part of your father’s regard. That you were diminished, that you aren’t _permitted_ to rule. Because of _me._ ” Cas meets his eyes. “Is all of that true, as well?”

Dean really doesn’t know who he wants to hurt more, right now: the psycho woman who he barely knows who thinks it’s okay to unload this sordid bullshit on _Dean’s husband,_ or the father who gave her the okay to do it.

On another time, Dean would make that same old joke about how they’re both terrible princes, and about how Dean didn’t want to rule any more than Cas did. It’s true, but even with as little as he knows he understands about cecaelia culture, he also knows it’s not the same damned thing.

Cas has lived here long enough to understand what _family_ means to Dean.

Dean blows out a long breath. “Some of it, maybe,” he answers, honestly, and he holds on tighter as Cas flinches. “But, you know what? I already knew I’d be a bad ruler, and at this point, my dad can seriously just screw himself with a tentacle.”

 _That_ gets him a reaction that he recognizes—his favorite, Cas’s head bopping delicately to the side and his eyes narrowing just slightly in the familiar little puzzled squint.

“Just an expression,” Dean teases, very gently.

“Oh,” Cas replies, before he frowns, eyes narrowing. “I don’t think I believe you.”

The laugh that shakes out of Dean has so much relief in it that it hurts a little. He kisses Cas’s palms—one, then the other. “Yeah, okay, we don’t really say that,” he murmurs. “But, Cas, look. You, um. You know I had sex before you, right?”

“Of course.” Cas doesn’t sound bothered by that, though, just like he’s never seemed to be bothered by it before. Maybe _that’s_ part of the reason Dean’s never bothered to play the numbers game with him… not just because he knows that Cas’s number is a grand total of _one_. “You’re a healthy and very attractive person. I’ve benefited from it, very much. That’s not the same as taking a partner, a _mate_.”

“Right.” Dean nods, and gently tangles his fingers through his husband’s. “So you get that _I_ chose you for my _husband_ , and I’d do it all over again. Every single damned time, buddy.” He tries on a shaky smile when Cas just looks stonily down at him. “Nothing ‘diminished’ about me, sweetheart, and _fuck_ anyone who calls you a nobody. You make me _happy_. And if anyone’s at fault, it ain’t you.” He looks at the small pile of colorful and soft things. “Why were you…”

“She said… she said that if I left, your position could be restored. You could… you could find a more suitable person. That you need one you can have children with, for Lebanon,” Cas says, and it’s not even a voice anymore. He looks into Dean’s eyes with that stare he has, the one that pries Dean open and leaves him naked. Dean can’t breathe for the horror—fuck, what a nightmare. “I thought of it. I thought of it, I went to… to… and…” he sighs, slow, longer than Dean thinks a human could breathe. “I couldn’t. I chose you, you’re _my_ mate and my family, and I couldn’t _leave_.”

Cas sounds so fucking sad about it that Dean doesn’t even know what to say.

“But you didn’t tell me, Dean. Not any of this. Why didn’t you tell me?”

The rasp of Cas’s voice would be a little scary if not for the pain that Dean can see in his eyes.

No, not pain. Betrayal.

‘Cause this might be Dean’s fault, but it’s still _Cas_ who got hit in the face with all of it.

“I…” and Dean doesn’t really have a good answer for that. Because it didn’t matter? Clearly, it really fucking does, and Dean not wanting it to doesn't make it so. Because Dean’s an insensitive ass and he really didn’t want to think about what it meant that he broke his engagement to someone else? Yeah, there’s that. Because he really didn’t want to have to explain all this to Cas, who has a hard time understanding _contracts,_ much less the idea of marrying someone out of obligation?

None of these reasons are putting Dean in a good light _at all,_ goddess fuck him.

Dean heaves a long sigh and sits back on his heels, shoving a hand through his own hair. “Fuck, maybe me and Amara _do_ deserve each other,” the joke slips out, muttered, self-deprecating and stupid and badly timed, and Dean knows just how _wrong_ he is when Cas’s whole body goes _rigid._

“No. No, _no,_ ” Cas hisses, and flings Dean onto the bed by the back of his jacket.

It’s not an exaggeration. Dean goes _flying,_ ass over teakettle, and lands so hard that he skids on the sheets, eyes wide. He has about a heartbeat to process Cas getting on the bed with him before there are hands grabbing him by his hip and shoulder, bruisingly hard, and Cas flips him onto his stomach.

Dean’s jacket is the first to go—buttons fly with tiny pings—and then his eyes go wider as his pants split along the seams with a sharp tearing noise, the cloth tossed to the ground even as Cas’s treasures go clattering off the comforter and onto the floor. “Cas—” he warns, and then his undershirt gives, too, between Cas’s strong hands. His smallclothes are shoved down his legs, pinning his knees together. Cas makes a hard, discontented noise as he tries to knock Dean’s thighs apart, then reaches down to rips Dean’s underwear off, too.

Oh, fuck.

Dean’s gentle husband does it like it requires zero effort at all.

Dean probably shouldn’t be even a little turned-on by the casual display of _strength_ , but—

“She cannot have you. No. You are _mine_ ,” Dean’s husband tells him, low and throaty and grating, more than a little animal.

The hard bite that Cas lands on the crest of Dean’s shoulder, hard enough that Dean yelps in surprise, should probably have been Dean’s second warning. Cas likes being bitten— _a lot_ —but he doesn’t normally chomp down like _that_.

Dean’s little sweetheart is playful and curious in bed. He wants to touch and taste _everything_. (Dean jokes about the toes, but those, too.) There are definitely worse things than having a husband who’s a little obsessed with Dean’s body, and Dean was a little worried that Cas might sort of taper off once the newness of all of it wore off for him, but he hasn’t.

(Though Dean will admit that he was shocked and more than a little insulted when, the first time Cas saw him naked, he commented in a tone of delight, “Oh! It’s so cute and smooth!”)

But Cas still hums with interest when he kisses Dean’s groin, giggles when it gets done back to him, because his ribs and neck and armpits aren’t at all ticklish, but the crease where his legs join his body is (and, in his true form, right where his mantle meets his upper half is, too, so there’s that). He _loves_ to bottom, moans like a star in a sex show and hitches his hips up to take Dean deeper, pulling his own knees up to his chest and open in a way that makes the inside of Dean’s brain go starry-night white. He all but coos when Dean sits on his cock and grinds them both to a slow, satisfying orgasm.

Dean’s still not a hundred percent sure how it’ll all work with Cas’s siphon, in his true form, ‘cause, well, possibility of _drowning,_ but he’s willing to give it a try. Getting fucked by his cotylus (hectocotylus, apparently, but Dean thinks that’s just too long, and it’s not what Cas calls it anyway; just call a dick a dick, basically) was, well, Dean’s gonna want to do _that_ again when the water’s warm enough that he’s not gonna end up with frostbite. It was really intense—holy _fuck_ , yes—but it was gentle, too, almost careful, getting opened up slow, bit by bit until he could take all of it, more than he ever thought he could. Dean could’ve used a warning about just _how_ big Cas’s cotylus would swell before he squirted all his come up Dean’s ass, but, well.

This isn’t that.

This isn’t any of that.

Dean gets one finger tugging him open, then a deep jab with two, lubricant oils running down his crack and thighs as Cas splashes them on.

And then Cas pushes into him. It’s rough, and Dean’s not quite prepped enough for this, but he breathes and whines into the burn of it. His pucker spasms, though, into the sudden stretch—too tight.

And Cas—‘cause he’s still Dean’s sweetheart, he’ll _always_ be Dean’s sweetheart—pauses. “Are you alright?” he asks, and the rasp of it is still angry, but it’s more careful now. His thumb presses against Dean’s jawline. Dean turns his face into Cas’s palm, grounding himself in that, breathing hard.

“Yeah,” Dean gasps, and it maybe isn’t exactly true, but it’s close enough. It feels like the first time he ever bottomed, when it was all still so goddamned overwhelming and he didn’t know how to relax or how to push into it, how to make it easier for himself, but he wanted it all the same.

He wants it now. Goddess, he wants it _so bad_.

“Don’t _lie_ to me,” Cas growls, and just with the sound of _that_ , well, that makes what was just a small white lie a moment before into truth. Dean’s ass squeezes around that thick, lovely cock around him like it’s trying to hold Cas in, and that bumps that fucking gorgeous angle of Cas’s cock up right where Dean wants it. He’s oversensitive enough that even as turned on as he is, the rub of the head of his husband’s cock against Dean’s prostate is _just_ shy of uncomfortable, almost too much pressure.

He can feel himself getting hard anyway.

Dean moans. “Not. Not lying. Fuck, _Cas_ ,” and he spreads his legs wider to fit him in, take him deeper. “Want you. Just you.”

And that’s the truth. That’s all the truth.

Cas doesn’t hesitate again before he shoves the rest of the way into him.

It’s a good thing Dean’s as lubed up as he is, and as _experienced_ as he is, because even with that, the first few thrusts are almost unbearably intense, they’re too much, and it _hurts._ For just about a second Dean thinks about telling Cas to stop. He will, Dean knows he will, if that’s what Dean wants—

He doesn’t tell him to stop, though. He doesn’t want him to.

Dean rides into being stuffed impossibly full, unprepared for the feel of it the way he hasn’t been in _years._ He’s trying to get his breath back so he can fucking _relax_ , but air is coming in small, stuttering, pathetic gasps as Cas doesn’t give him a chance to try—just yanks himself out and then fills Dean up all over again, holding him down with a hand on his shoulder. Dean’s back arches when Cas—accidentally, he thinks—rubs against his prostate again.

Without his earlier shock tightening through his stomach, that feels good now, just plain _good,_ and against the contrast of the slow-fading pain it’s pure electricity. It loosens Dean up, makes his limbs remember just how much he enjoys this, makes his ass tug and squeeze a little for more.

Cas moans, behind him, loud and wanton, as the strokes come easier now, and isn’t that a pretty sound? So damned familiar. Cas grits out something in his own language, hoarse, but Dean doesn’t have an answer for him. His cock feels like it’s got a second heartbeat, beating in time with his pulse as it rubs against the sheets under him. He thinks there’s no way Cas can keep up this pace—in and out, each thrust all the way from root to tip, not even giving either of them a second to just slow down and grind.

But Cas doesn’t get any gentler, and Dean can’t even push back against him to meet the thrusts, because there’s no rhythm to it. It’s not a dance, and there’s no give-and-take. He can’t do anything but brace himself against the bed, one hand on the headboard to keep from being shoved against it, the other clenching into the sheets as his husband slams into him, over and over, their hips slapping.

Dean calls what they do with and to each other normally ‘fucking’—or mating, heh; the term’s kind of grown on him, to be honest. But it’s always intimate, good and sweet.

This isn’t lovemaking, it’s most definitely _fucking,_ and he cries out into it.

It’s… good. He’s good, he _likes_ this, Cas pounding into him. It’s actually… he… oh fuck, _oh fuck._

His ass is open and lube-wet and just taking Cas in so _easily_ now. Cas basically spread him open with just his cock, and none of it should feel all that good—Dean would never have let anyone else do it, but this is _Cas._ This is Dean’s sweetheart, and Dean trusts him. He’ll always trust him. So he ducks his chin and rests his forehead on the sheets. Realizes the noises he’s making sound like sobs. He doesn’t care.

Dean doesn’t think he can orgasm from this, and he doesn’t even fucking _care_ , all he wants to do is lie here and feel, his whole body shaking and rocking with just how much Cas—how much his _husband—_ wants him.

Dean keeps thinking that all the way until he comes so hard his shoulders arch right off the bed and his teeth clack.

He doesn’t know the flash and pleasure of it is coming until it’s there, until his cock is bobbing and the rush of come through him feels like a fucking _fire hose._ Dean feels it spurt; feels it drip, rolling hot onto the bedsheets as Cas thrusts again. He bites the side of his cheek so hard he tastes blood, but the sting of it is tiny and bright and savory.

 _That,_ of all the damnable things, makes Cas pause. Maybe to feel it. Maybe ‘cause Dean’s rippling too tight around him for him to keep moving the way he was. Maybe he smells the blood. But he pauses, and Dean _whines_.

“Don’t stop, sweetheart, don’t—”

Cas doesn’t.

He doesn’t, and by the time he spills into Dean, wet and pulsing and _good,_ Dean can’t hold himself up anymore, his hands slack where they rest against the headboard. He’s keening into the sheets, a little helpless. A little broken. He doesn’t want Cas to pull out, but he can’t find the words to say so, and when he’s left empty and rolled back over onto his back, he moans a little. He feels come drip right out from him; fuck, he’s so open.

But that’s his husband’s beloved face hovering over his, red-eyed at the corners.

(Cecaelia don’t cry, a weirdly alert part of Dean’s brain reminds him, because they don’t make tears. They have a second eyelid that protects them when they’re underwater, and it’s what keeps their eyes from drying out. It’s what makes Dean feel a little better about the fact that he might’ve teared up a little at their wedding, and Cas didn’t.)

“Oh, _Dean_. Dean, I’m sorry. Are you alright? I’m… I’m so…” and Cas trails off.

“M’fine.” Dean blinks, very slowly up at him. He lifts up a hand—his fingers are shaking—and runs the back of one lightly down Cas’s cheekbones, the soft plane of his cheek. “ _Are_ you sorry?” he asks, honestly curious.

Cas swallows, slowly. Dean sees the ripple of it moving down his throat in the lamplight. “No,” he whispers. “No, I wanted to do that.”

Because, at the end of the day, Cas is the single most genuine creature Dean’s ever met.

“Good,” Dean tells him, satisfied. “Come here.” He pulls him in.

They’re lying in silence for long enough that Cas’s skin starts to cool again, and he shivers. Dean wraps his arms closer around him and gently nudges him to the bed, so there’s less of him exposed to the air. It’s not that cold in the room, but for someone who doesn’t like to wear clothes—and swims in _really cold_ water—Cas is sort of temperature-sensitive.

“So… was that a cecaelia thing? ‘Cause, _fuck_ , sweetheart,” Dean murmurs, rubbing his face into Cas’s neck. Well, there’s going to be no horseback riding tomorrow, that’s for sure. He reaches back to touch his rim, and winces. Looks like Dean’s going to be drawing up those scouting patterns tomorrow rather than riding the trails himself. Well, Jo’ll be happy, at least. “You guys go into season or something?” he teases, gently.

“What? Um. No, males don’t, I just… no,” Cas mumbles, and presses his face shyly into Dean’s hair. Dean can feel the vibration of him talking as much as he can hear it. “I had to… I had to mark you with my body, I had to _have_ you. I didn’t… I didn’t like that thought. That you might be someone else’s. That… that you _were_ someone else’s.”

“I ain’t that fond of it either, sweetheart,” Dean answers, and he runs his hand down Cas’s hip, cupping the warm, elegant curve of bone that he thinks of as his, all his. “But you got the second part of that wrong. Pretty sure I’ve never been anyone’s but yours. That’s kind of how this thing works.”

He didn’t know he needed to say it. He didn’t know Cas needed to hear it. He realizes it when his sweetheart husband melts against him, warm and quiet again.

“ _I’m_ sorry,” Dean finally says, and he drops a kiss against Cas’s neck. “I just… I didn’t think. I guess I _hoped_ it wouldn’t matter. Which… was pretty dumb.” He sighs, ruefully. “I guess we’re still figuring things out. But… you do make me happy, Cas. You know that, right?”

After a moment that almost stops Dean’s heart, Cas nods.

“I would like to go on the honeymoon that you mentioned,” Cas tells him, finally. “On the ocean.”

Dean smiles, stupidly pleased, and cuddles him closer. “Yeah,” he murmurs, and turns his face up just enough to grab a kiss from those plush pink lips. “Okay.” He won’t tell Cas that he’s sort of been low-key planning on it already, for when the weather gets just a little warmer again, so Dean doesn’t freeze if he wants to dive off and swim with Cas some. He’s even got a little boat set up for it and all, big enough for extended time off, a couple of mods so it doesn’t need a full crew. Just them.

And after this, Dean knows he’s _really_ going to need some time away.

“I’m going to find a witch who knows a transformation spell, and I don’t care if it’s forbidden,” Cas continues, and Dean sucks in a small, sharp breath. “I want you in the depths with me—I want to show you my caves, and the wrecks where I used to play, and how enjoyable a current is to ride. I want to show you how nice it is to tuck your sea-arms under deep sand, especially near the hot vents.” Cas blinks earnestly at him and kisses his forehead. “It’s nicer than toes in it, I promise.”

Again with the _toes_. Dean has to laugh, all the better because it comes so unexpected, and the sudden shock of love he’s feeling is almost too much—

But Cas isn’t done. He’s looking right into Dean’s eyes, and Dean can’t look away when he continues, “I am going to mate you in the deep, cold water. I will tease your siphon open and lick your suckers, and keep my cotylus inside you for hours. I’ll fill you over and over until the water around is cloudy with semen. And then I will expect you to do the same to me. They’ll see our colors glowing and mingling for _miles._ ”

Oh. Holy. _Shit._

The noise that comes out of Dean isn’t human. It’s not cecaelia, either. Well, it might be. It comes from somewhere so deep and shaky that it tremors Dean’s throat. He just stopped feeling his tongue.

“And if someone comes to investigate our scents and our lights, Dean, I don’t care about these ridiculous two-legger notions of modesty.” Cas’s voice is harsh and rough and a threat, but it might be a promise, too. His eyes are getting that little glowing edge again. “For your sake, I have covered us, but in the water, I will _not_ stop and hide from anyone who might watch us mate and know that we’re beautiful, that we belong to each other. That’s what mating colors are _for._ So please know what you are agreeing to, beloved.”

That… alright, maybe Dean’s brain is just a little too blissed-out, and the images that are running through his mind are obscene even for _him,_ but what comes out of his mouth is, “You’d like that, huh? Everyone seeing us like that.”

But Cas, so close against him, shudders. His mouth goes soft and hungry, but more than that, Dean actually _feels_ his skin go warmer.

Huh. Well, then.

It’s not that Dean doesn’t understand the feeling of wanting to show off his pretty husband, ‘cause he does it all the time. He just, uh, does it with all of their clothes on.

But… looks like Dean’s still got a couple of things to learn about Cas’s culture. And he hasn’t been doing _nearly_ enough to meet him halfway, has he.

“Huh. Well… I guess we can try it,” he agrees, and he all-but-feels his sweetheart brighten right up against him. Yeah, Dean knows he just agreed to some kind of freaky experimental magic that _probably_ is going to come at some kind of cost of blood or memory or something rather than just plain money, and most likely to fucking in the _wide open ocean_ because, and it makes a weird sort of sense, that’s just kind of what octopus people do.

But, what the hell.

“Yeah… let’s do that. Sure. I bet it’ll be fun to have tentacles,” Dean teases, nibbling on the lobe of Cas’s ear.

This time, Cas pinches him.

~fin~

**Author's Note:**

> Gosh darn it, porn snuck into my Suptobers... I was trying to avoid that, because there lies a very slippery slope. *sigh*
> 
> Sorry, no tentacle sex (Octo!Cas: Sea-arms, and it is a cotylus!) in this one. However, I think there's going to be one more for them before the month ends. Who knows, maybe Dean will even get to top next time! (Sigh.)
> 
> For those of you who have an opinion about this: siphon sex, or undersea honeymoon hijinks?


End file.
